Patent Literature 1 discloses a choke coil installed between a power converter and a power system, in which, in a core in which the upper ends and lower ends of three leg portions are connected to each other by using two connection portions, coils are wound on the three leg portions and a yoke is connected between parts of the two connection portions, which extend toward the right side. With this structure, according to Patent Literature 1, it is described that it is possible to obtain a choke coil that can maintain a predetermined inductance value for both the normal mode and the common mode.